I happen to have a set of stock shocks and a stock compressor that I rebuilt.. it actually pushes more air than a stock one due to the fact that I had to bore out the outlet.. so the truck will raise slightly faster..
if you want it, let me know..
as for testing the system, once the compressor stopped working for me, I simply took it out.. saved about 5lbs weight wise and i never have to worry about it breaking again. Removing all the wiring is a bitch, I still haven't finished.. just kinda tied it up there out of the way.
the fuse is clearly marked.. its something like elec, i forget it was easy to figure out.. when i had my truck on a flatbed, chaining it down made the pump go crazy.. so i had to pull the fuse.